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Natural soundscapes of lowland river habitats and the potential threat of urban noise pollution to migratory fish
2024
te Velde, Kees | Mairo, Amy | Peeters, Edwin T.H.M. | Winter, Hendrik V. | Tudorache, Christian | Slabbekoorn, Hans
Migratory fish populations have experienced great declines, and considerable effort have been put into reducing stressors, such as chemical pollution and physical barriers. However, the importance of natural sounds as an information source and potential problems caused by noise pollution remain largely unexplored. The spatial distribution of sound sources and variation in propagation characteristics could provide migratory fish with acoustic cues about habitat suitability, predator presence, food availability and conspecific presence. We here investigated the relationship between natural soundscapes and local river conditions and we explored the presence of human-related sounds in these natural soundscapes. We found that 1a) natural river sound profiles vary with river scale and cross-sectional position, and that 1b) depth, width, water velocity, and distance from shore were all significant factors in explaining local soundscape variation. We also found 2a) audible human activities in almost all our underwater recordings and urban and suburban river parts had elevated sound levels relative to rural river parts. Furthermore, 2b) daytime levels were louder than night time sound levels, and bridges and nearby road traffic were much more prominent with diurnal and weekly patterns of anthropogenic noise in the river systems. We believe our data show high potential for natural soundscapes of low-land river habitat to serve as important environmental cues to migratory fish. However, anthropogenic noise may be particularly problematic due to the omnipresence, and relatively loud levels relative to the modest dynamic range of the natural sound sources, in these slow-flowing freshwater systems.
Show more [+] Less [-]Plastic does not simply flow into the sea : River transport dynamics affected by tides and floating plants
2024
Lotcheris, R.A. | Schreyers, L.J. | Bui, T.K.L. | Thi, K.V.L. | Nguyen, H.Q. | Vermeulen, B. | van Emmerik, T.H.M.
Plastic pollution is ubiquitous in aquatic environments worldwide. Rivers connect terrestrial and marine ecosystems, playing a key role in the transport of land-based plastic waste towards the sea. Emerging research suggests that in estuaries and tidal rivers, tidal dynamics play a significant role in plastic transport and retention dynamics. To date, observations in these systems have been limited, and plastic transport dynamics during single tidal cycles remain poorly understood. Here, we investigated plastic transport, trapping, and re-mobilization of macroplastics (> 0.5 cm) in the Saigon River, focusing on short-term dynamics of individual tidal cycles. We used GPS trackers, released at different stages of the tidal cycle (ebb, flood, neap, spring). Plastic items demonstrated dynamic and intermittent transport behavior. Items spent almost half of the time (49%) temporarily stopped, mainly due to their entrapment in vegetation, infrastructure, or deposition on riverbanks. Items were almost always re-mobilized within 10 h (85%), leading to successive phases of stopping and transport. Tidal dynamics also resulted in bidirectional transport of plastic items, with median daily total transport distance within the 40 km study reach (8.9 km day−1) over four times larger than the median daily net distance (2.0 km day−1). The median retention time of plastic items within the reach was 21 days (mean = 202 days). In total, 81% of the retrieved items were trapped within water hyacinths, emphasizing the important role of floating vegetation on river plastic transport dynamics. With this paper, we aim to provide data-driven insights into macroplastic transport and retention dynamics in a tropical tidal river. These are crucial in the design of effective intervention and monitoring strategies, and estimating net plastic emission from rivers into the sea.
Show more [+] Less [-]Estimating plastic pollution in rivers through harmonized monitoring strategies
2023
van Emmerik, Tim H.M. | Kirschke, Sabrina | Schreyers, Louise J. | Nath, Shuvojit | Schmidt, Christian | Wendt-Potthoff, Katrin
Plastics in rivers and lakes have direct local impact, and may also reach the world's oceans. Monitoring river plastic pollution is therefore key to quantify, understand and reduce plastics in all aquatic ecosystems. The lack of harmonization between ongoing monitoring efforts compromises the direct comparison and combination of available data. The United Nations Environment Programme (UNEP) launched guidelines on freshwater plastic monitoring, to provide a starting point for practitioners and scientists towards harmonized data collection, analysis, and reporting. We developed a five-step workflow to support to design effective plastic monitoring strategies. The workflow was applied to three rivers (Rhine, Mekong and Odaw) across relevant gradients, including geography, hydrology, and plastic pollution levels. We show that despite the simplicity of the selected methods and the limited duration of the data collection, our harmonized approach provides crucial insights in the state of plastic pollution in very different river basins globally.
Show more [+] Less [-]Estimating plastic pollution in rivers through harmonized monitoring strategies
2023
van Emmerik, Tim H.M. | Kirschke, Sabrina | Schreyers, Louise J. | Nath, Shuvojit | Schmidt, Christian | Wendt-Potthoff, Katrin
Plastics in rivers and lakes have direct local impact, and may also reach the world's oceans. Monitoring river plastic pollution is therefore key to quantify, understand and reduce plastics in all aquatic ecosystems. The lack of harmonization between ongoing monitoring efforts compromises the direct comparison and combination of available data. The United Nations Environment Programme (UNEP) launched guidelines on freshwater plastic monitoring, to provide a starting point for practitioners and scientists towards harmonized data collection, analysis, and reporting. We developed a five-step workflow to support to design effective plastic monitoring strategies. The workflow was applied to three rivers (Rhine, Mekong and Odaw) across relevant gradients, including geography, hydrology, and plastic pollution levels. We show that despite the simplicity of the selected methods and the limited duration of the data collection, our harmonized approach provides crucial insights in the state of plastic pollution in very different river basins globally.
Show more [+] Less [-]Wastewater irrigation effect on soil, crop and environment: a pilot scale study at Irbid, Jordan
1998
Shahalam, A. (Ohio State Univ., Coshocton, OH (USA). Outlying Station) | Abu-Zahra, B.M. | Jaradat, A.
Whole-catchment liming at Tjoennstrond, Norway: an 11-year record
1997
Traaen, T.S. (Norwegian Inst. for Water Research, Oslo (Norway).) | Frogner, T. | Hindar, A. | Kleiven, E. | Lande, A. | Wright, R.F.
The effect of drainage on nutrient release from fen peat and its implications for water quality - a laboratory simulation
1990
Heathwaite, A.L. (Sheffield Univ. (UK). Dept. of Geography)
Differences in acid tolerance during the early life stages of three strains of brook trout, Salvelinus fontinalis
1989
Hurley, G.V. (Hurley Fisheries Consulting Ltd., Dartmouth, N.S. (Canada)) | Foyle, T.P. | White, W.J.
Quality of water wells in an agricultural area in the city of La Plata, Argentina
1998
Marteau, S.A. (Universidad Technologica Nacional, La Plata, Buenos Aires (Argentina). Dept. of Science and Technology) | Alberino, J.C. | Ripoli, J.L. | Rosato, M.E.
Biology and chemistry of three Pennsylvania lakes: responses to acid precipitation
1986
Bradt, P.T. (Centre for Marine and Environmental Studies, Bethlehem, PA (USA)) | Dudley, J.L. | Berg, M.B. | Barrasso, D.S.